1 // SPDX-License-Identifier: GPL-2.0 2 #include <stdio.h> 3 #include <linux/bpf.h> 4 #include <unistd.h> 5 #include <linux/filter.h> 6 #include <linux/seccomp.h> 7 #include <sys/prctl.h> 8 #include <bpf/bpf.h> 9 #include "bpf_load.h" 10 #include <sys/resource.h> 11 #include "trace_helpers.h" 12 13 /* install fake seccomp program to enable seccomp code path inside the kernel, 14 * so that our kprobe attached to seccomp_phase1() can be triggered 15 */ 16 static void install_accept_all_seccomp(void) 17 { 18 struct sock_filter filter[] = { 19 BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW), 20 }; 21 struct sock_fprog prog = { 22 .len = (unsigned short)(sizeof(filter)/sizeof(filter[0])), 23 .filter = filter, 24 }; 25 if (prctl(PR_SET_SECCOMP, 2, &prog)) 26 perror("prctl"); 27 } 28 29 int main(int ac, char **argv) 30 { 31 FILE *f; 32 char filename[256]; 33 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; 34 35 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); 36 setrlimit(RLIMIT_MEMLOCK, &r); 37 38 if (load_bpf_file(filename)) { 39 printf("%s", bpf_log_buf); 40 return 1; 41 } 42 43 install_accept_all_seccomp(); 44 45 f = popen("dd if=/dev/zero of=/dev/null count=5", "r"); 46 (void) f; 47 48 read_trace_pipe(); 49 50 return 0; 51 } 52